CompTIA DataSys+ (DS0-001)Database FundamentalsMedium
A data engineer is working with a legacy database that stores customer addresses in a single `Address` column (e.g., '123 Main St, Anytown, CA 90210'). The business now requires separate fields for `Street`, `City`, `State`, and `ZipCode` for reporting and targeted marketing. This change is an effort to move the database towards which normal form?
- ASecond Normal Form (2NF)
- BBoyce-Codd Normal Form (BCNF)
- CThird Normal Form (3NF)
- DFirst Normal Form (1NF)
Show answer & explanationAnswer & explanation
Correct answer: D. First Normal Form (1NF)
Decomposing the `Address` column into `Street`, `City`, `State`, and `ZipCode` ensures that each column contains atomic values, meaning each piece of information is indivisible. This directly addresses the requirement for First Normal Form (1NF).
Why the other options are wrong
- A. 2NF deals with partial dependencies on a composite primary key, which is not the primary concern here.
- B. BCNF is a stricter version of 3NF, addressing more complex dependency scenarios, which is beyond the scope of this atomic value issue.
- C. 3NF deals with transitive dependencies, ensuring non-key attributes depend only on the primary key, not on other non-key attributes.
First Normal Form (1NF)
The first level of database normalization, requiring that all columns in a table contain atomic (indivisible) values and that there are no repeating groups of columns.
- Each cell contains a single value.
- No repeating groups of columns.
- Eliminates multi-valued attributes.
Memory trick: 1NF: Atomic! 2NF: No partial! 3NF: No transitive!